The present invention concerns improvements relating to jewelry illumination, and more particularly, though not exclusively, relates to improvements concerning an article of jewelry including a jewel and having a light source incorporated in the article for illuminating the jewel.
A jewel stone is an optical system that is manufactured from material that is not opaque to light. It may be a natural mineral or a manufactured artificial mineral or optical compound. The design is such that when illuminated and viewed from the front the light falling upon it is largely refracted, internally reflected and returned to the front so that the jewel stone appears bright. The refraction and reflection process may also change the color of the light emitted after passing through the jewel stone and re-emerging. Jewelry including one or more jewel stones is generally designed so that it does not pass light from the front to the rear. Thus when illuminated from the front and viewed from the rear, the jewel stones appear dull.
The process of design and manufacture of jewelry often involves cutting the mineral into carefully designed angles and facets that are intended to achieve the desired optical effects of causing the front surface to sparkle or scintillate as the refraction and reflection occurs. Such optical effects occur when the jewel stones catch external light at certain incident angles and reflect or diffuse the light.
FIGS. 28(a)-(c) show side, top and bottom views of a brilliant cut jewel stone 210. As shown in FIG. 28(a), the top part 212 is called a xe2x80x9ccrownxe2x80x9d, the bottom part 216 is called a xe2x80x9cpavilionxe2x80x9d, and the connecting part 214 between the crown 212 and the pavilion 216 is called a xe2x80x9cgirdlexe2x80x9d. As shown in FIG. 28(b), the crown 212 comprises the face of the brilliant cut called a xe2x80x9ctablexe2x80x9d 222 and inclined surfaces called xe2x80x9ctop facetsxe2x80x9d including xe2x80x9cstarsxe2x80x9d 220 surrounding the table 222, xe2x80x9cbezelsxe2x80x9d 218 surrounding the stars 220 and xe2x80x9ctop girdle facetsxe2x80x9d 224 located between the bezels 218 and girdle 214. As shown in FIG. 28(c), the pavilion 216 comprises the base called a xe2x80x9cculetxe2x80x9d 228 and inclined surfaces called xe2x80x9cpavilion facetsxe2x80x9d including xe2x80x9cpavilionsxe2x80x9d 226 surrounding the culet 228 and xe2x80x9cbottom girdle facetsxe2x80x9d 230 located between the pavilions 226 and the girdle 214.
Such brilliant cut jewel stones may be made from a wide number of materials, for example , diamonds or cubic zirconium which is a material approaching the hardness of diamond and often used as an artificial replacement.
Scintillation is the word generally associated with jewelry that sparkles. The scintillation effect is most pronounced when correctly designed jewels are illuminated with a point source such as a candle and the jewel is moved through some angular rotation. Very small angular movements can provide substantial scintillation by virtue of the multiple internal reflections, refractions and dispersions which are given words such as fire and brilliance.
Each of FIGS. 27(a)-(f) shows a cross section of a brilliant cut jewel stone 200 indicating the way in which light 202 falling on a surface 204 of each jewel stone 200 is refracted by the surface 204, internally reflected by the pavilion facets and then refracted for a second time by the surface 204 as it leaves the front of the jewel stone 200. When the light falling on the front face of the jewel stone is returned, the jewel stone appears to sparkle.
When proportions of the jewel stone are perfect as shown in FIG. 27(a), all light gets reflected back, either via the table or the top facets, so that brilliance is achieved. However, as shown in FIGS. 27(b) and 27(c), if the pavilion is too deep or too shallow, part of the rays of incoming light xe2x80x9cescapesxe2x80x9d through pavilion facets. As shown in FIGS. 27(d)-(e), if the crown is too low, less refraction occurs by the crown facets. Thus, brilliance is most dependent on the angles of pavilion facets, and fire depends on angles of crown facets.
The sparkling is also due in part to the dispersion of the generally white light and its breakdown into a number of constituent colors, each of which emerges with a slightly different beam angle. FIG. 29 shows a curve of variation of refraction coefficient for various different colors of light which gives an indication and measurement of this dispersion effect.
Although jewel stones are generally designed to have optical effect, when external light is not strong enough, little optical effect including scintillation effect occurs and the colors of the jewel stones are not readily visible. Further, when there is no relative movement between jewelry, the viewer and external light, jewel stones do not produce any optical effect even if enough ambient light is present.
Artificial illumination of a jewel in an article of jewelry has previously been described in GB 1 352 835, where a translucent jewel can be illuminated intermittently by battery-powered light-emitting diodes provided on the non-viewing side of the article. The LED""s can be pulsed by signals from an control circuit which are generated by sensing the wearer""s movement, or external sound or light.
Another artificially illuminated article of jewelry is described in U.S. Pat. No. 4,973,835 where a light emitter is provided near a transparent body (jewel). The light emitter is frequency pulse generators and a light detector. When the signal processor receives a low-light signal, the light detector signal being sampled at the frequency of one of the pulse generators, the processor controls the light-emission timing to cause the light emitter to emit light at the frequency of the other frequency generator. Otherwise, the light emitter is not driven and the jewel is not illuminated by the light emitter.
In the prior art, the jewel illumination is at best rather crude. In both GB 1 352 835 and U.S. Pat. No. 4,973,835, the pulsing of the LEDs is entirely dependent on external conditions such that the illumination lacks consistency. During periods of time where the sensed matter does not change, the illumination is inactive. For example, in GB 1 352 835 when a motion sensing device is employed and the user is stationary, light pulses are not generated. Also in the device of U.S. Pat. No. 4,973,835 light pulses are not generated in bright light conditions. Furthermore, in low-light conditions, the U.S. Pat. No. 4,973,835 device can only produce a consistent repeating pattern of light pulses at a regular frequency from which it is apparent that there is artificial lighting of the jewel. As digital pulses are used in both of the above described prior art arrangements to drive the LEDs, the duration and the intensities of the light pulses emitted from each LED are constant. The resultant light output does not mimic natural illumination of the jewel.
All of the above features of the prior art devices make the artificial illumination of the jewel used therein readily distinguishable from natural light illumination of a jewel. More particularly, the prior art devices produce illumination light pulses which are either too regular or too irregular to be of effective use in simulating the so called natural optical effects such as sparkle or scintillation of the jewel.
An object of the present invention is to provide an article of jewelry where the jewel is artificially illuminated in such a way as to simulate realistic optimum natural illumination. The desired illumination is that which generates simulated natural optical effects in the jewel such as sparkle, scintillation and glow.
According to one aspect of the present invention there is provided an article of jewelry arranged to simulate natural optical effects, such as sparkle and scintillation, the article comprising: a jewel; a light source incorporated in the article of jewelry for emitting light so as to illuminate the jewel; and means for controlling the light source to emit light pulses which are variable in intensity, thereby simulating said natural optical effects of the jewel.
By incorporating the light source in the article of jewelry and controlling the intensity of each emitted light pulse, the jewel interacts with light emitted from the light source and scintillates, sparkles and/or glows by itself. Thus, an article of jewelry embodying the present invention can maintain or enhance its attraction in the dark and in the presence of ambient light. The stimulation of optical effects is performed to simulate natural optical effects of the jewel.
The term xe2x80x98jewelxe2x80x99 is to be construed broadly throughout this description to mean any article or material having optical reflective and/or refractive properties. Examples of such jewels are one or more precious stones such as diamonds or rubies, semiprecious stones, imitations of these stones made form artificial materials or even small reflective metallic objects. These jewels may be combined aesthetically as desired.
The generation of light pulses in this way simulates the natural internal optical reflections of an externally illuminated jewel. More specifically, by use of illumination pulses which are not of a constant intensity, the movement between the jewel and an external light source is simulated.
These effects are preferably obtained through the use of extremely small internal light sources, such as light emitting diodes, which are controlled to alter the position, number, intensity and color of the illuminated gemstones in a pseudo-random pattern although other deliberately repetitive patterns are possible. Because of the requirement for a natural appearance, the illumination patterns are more subtle and complex than have been used previously.
Preferably the control means is arranged to cause the light means to emit light pulses in which the light output intensity is controllably varied along the duration of each pulse. In this way, the intensity profile of each light output pulse can be controlled to accurately mimic the profile of reflected or refracted light pulses seen by natural illumination of the jewel or gemstone. For example, by varying the amplitude (intensity) of a given light pulse over time, the jewel can be made to appear to glow. In a presently preferred embodiment, the light intensity is made to decrease along the duration of each output light pulse. This simulates scintillation profiles seen in natural illumination of gemstones.
In addition or alternatively, the control means may be arranged to cause the light means to emit light pulses in which the peak light output intensity is controllably varied along a sequence of light output pulses. The light output produced in this way simulates gently flickering reflection. This effect can be enhanced by randomizing the selection of the peak light output intensity of each light output pulse.
Preferably the control means is arranged to cause the light source to emit a series of light pulses in which each light pulse has a controllably variable duration. This advantageously enhances the overall simulation of natural illumination of the jewel. Preferably the selected duration for each light pulse is randomized to further improve the realism of the artificial illumination.
The control means preferably directly energises the light sources and controls the precise light output from each light source, such as the pattern, amplitude and duration of light pulse emission. For example, an application specific integrated circuit (ASIC), such as a complementary metal-oxide semiconductor (CMOS) ASIC, may be used as a suitable control means. Optimal patterns may be determined experimentally and different effects may be obtained by different patterns.
In a presently preferred embodiment, relative movement is also simulated by providing a plurality of spaced apart light sources, each light source being arranged to illuminate the jewel from a different location, and the control means is arranged to apply electrical pulses to selected ones of said light sources. The selection of the particular light source can be randomized such that the light reaching the viewer appears to come from different positions within the jewel which represents a more realistic optical movement effect. The light sources can be positioned symmetrically about the jewel and the control means can be arranged to cause emission of light pulses from the light sources in a sequential manner. This arrangement can produce a rotational optical effect which has a particular advantage of increased attractiveness in jewels that are designed to have a radial reflection or refraction elements.
A jewel may be coupled to more than one light source so as to stimulate different optical effects from different parts of the jewel as stated above. If a jewel is not located close to a light source and would not easily receive light emitted from the light source, then optical guiding means such as an optical fiber may be provided between the jewel and the light source.
In one embodiment of the present invention, the light sources are arranged to emit different colored light pulses. This advantageously provides simulation of the natural refractive optical effects that are seen in an externally illuminated jewel. Advantageously, realistic visual effects can be produced by the article of jewelry by arranging the control means to vary the color by random selection of the color of the next pulse to be emitted.
In another embodiment of the present invention, the light sources are combined to form a suitable light source for emitting multiple modes of light. Especially, an LED array having a plurality of LEDs is suitably used.
It is desirable to use a multi-color light source or a white light source, which can be refracted and separated into its constituent wavelength components. LEDs currently available are in individual colors, which are close to monochromatic. Multi-color LEDs or white LEDs are not currently available. Accordingly, it is preferable to utilise more than one color LED at a given location in order to produce simulation of the same optical effects as a multi-color or white light source. For example, when red, green and blue LEDs are energized, some composite light output approaches white light.
Preferably, the control means is arranged to generate multiple sequences of pulses, each sequence being independent from the other, for driving the light sources simultaneously. In this way, when different color light sources are activated simultaneously, the natural optical effect of bicolor or tricolor dispersion can be simulated.
It is further preferable that the control means is arranged to vary the light emission in response to changes in ambient conditions and/or movement of the article of jewelry. To this end, the article of jewelry may comprise detecting means for detecting such changes in ambient conditions and/or movement of the article of jewelry. The detecting means may comprise one or more environmental sensors which detect one or more of parameters including ambient temperature, ambient noise, ambient light, skin temperature and pulse rate of the wearer of the article of jewelry. Any kind of sensor may be used for this purpose so long as it is small enough to be incorporated in a particular design of the article of jewelry. For example, a photodiode may be used to detect ambient light levels.
The control means preferably performs an algorithm to change the patterns, amplitude and/or duration of the light emission in response to the detection of the detecting means. For example, the controller may increase the amplitude and frequency of impulses of light emission as darkness falls and the activity of the wearer of the article of jewelry increases.
In order further to stimulate optical effects, the article of jewelry may also have a reflector or a mechanical system incorporated in the article of jewelry. A mirror may be used as a suitable reflector to reflect light emitted from the light source or light reflected by the jewel or other reflectors. The mechanical system may comprise vibration means or a movable member which vibrates light emitted from the light source. The movable member may be a rotatable reflector or rotatable disc or shutter pierced to create differing patterns of light.
It is preferable to provide the light source without affecting the performance of the jewel when viewed normally with front lighting. To this end, it is preferable that the direct visual path from the light source to the viewer is minimized. That is, all light reaching the viewer is preferably internally reflected in the jewel at least once and/or refracted at least once before reaching the eye of the viewer.
In order to produce such reflection and refraction, it is preferable to position the light source in a cavity provided in the jewel, so as to allow the light source to be centered somewhere within the jewel. Through the cavity, the light source may be connected to the control means.
Instead of positioning the light source itself in the cavity, an end of an optical guiding means may be brought into the cavity, and the light source may be located outside the jewel.
The cavity is preferably tapered from a non-viewing side of the jewel toward the interior of the jewel so as to reflect, by walls of the cavity, the light falling on the front of the jewel back towards the viewer. A conical cavity or a pyramidal cavity may be suitable.
It is preferable to provide, on the non-viewing side of the jewel, a base plate having a reflecting surface to reflect the light falling on the front of the jewel back towards the viewer.
It is also preferable to provide an opaque reflective coating or an opaque mirror within the cavity. The opaque reflective coating or mirror has two purposes: firstly to block the direct path of light from the light source to the eye of the viewer; and secondly to reflect the light from the light source back to a base reflecting surface provided at the non-viewing side of the jewel, which then in turn re-reflects it back towards the front (viewing side) of the jewel.
A further reflective mirror may be incorporated at the entrance to the cavity, such that all light from the reverse emission of the light source can be reflected back up into the jewel to add to the light emitted directly into the jewel.
An alternative to positioning the light source within a cavity is to utilize a so called xe2x80x98special cutxe2x80x99 feature. The special cut feature is a prismatic cavity provided in the jewel stone preferably at a non-viewing side of the stone. The light source or sources are provided laterally spaced apart from the prismatic cavity and have their light beam paths directed towards the prismatic cavity. The light sources are positioned such that their light beam paths are approximately transverse to the direction required to direct light out of the jewel to the viewer. However, when light falls one the prismatic cavity, it is reflected at substantially 90xc2x0 such that it then is directed to the viewer""s eye. Similarly to the pyramidal cavity described above, the special cut feature also advantageously does not have a direct illumination path from the light source to the viewer""s eye. Furthermore, the special cut feature advantageously removes the need for a metallized portion in the cavity, provides greater freedom to the jewelry designer in the positioning of the light source(s) and allows more that one light source to be used concurrently in the illumination of the jewel.
A natural effect that occurs when reflection and refraction take place from a front illuminated cut jewel is called by various names but xe2x80x98sparklexe2x80x99 is one suitable description. During the sparkle effect some parts of the jewel are seen as bright and others remain less bright. Moving the jewel causes a change in the points of light that are generated.
In some of the above described embodiments of the present invention, problems can occur sometimes in the effective simulation of the sparkle effect because of the general scattered nature of the light emitted by an LED light source. The internal reflections that take place when a cut stone jewel is illuminated by such an LED light source are seen by the viewer as a uniformity of color and intensity throughout the jewel. Such an appearance is quite unlike the sparkle effect described above.
It has been found that the sparkle effect can be obtained from LEDs in the above described articles of jewelry by collimating the output of each LED light source. In an embodiment of the present invention, collimation is achieved simply by providing a miniature collimating lens adjacent the output of each LED. A collimated light source has the effect of generating high and low points in the viewer""s image and this closely resembles the natural lighting effects associated with xe2x80x98sparklexe2x80x99. Movement of the jewel is emulated by the variable intensity light pulses of the present invention.
Preferably two or more collimated LED""s located at different positions on the non-viewing side of the jewel are provided in the article of jewelry. The collimated light output of each LED produces a unique spatial illumination pattern within the jewel. When switching between the spatial illumination patterns the xe2x80x98sparklexe2x80x99 effect seems to move within the jewel.
The above described effects can all be combined together or combined selectively together to produce an extremely realistic simulation of the natural optical effects of an externally illuminated jewel.
The article of jewelry is assembled into an artistic aesthetic design that is found to be attractive in its own right. The article of jewelry may be a final product, such as a piece of jewelry, pendant, bracelet, brooch, watch etc., or may be a module which is ready to be assembled with a frame of such a final product.
Thus, according to the article of jewelry of the present invention, an optical device is combined with a jewel to produce a hybrid construction of the jewel in which the jewel is stimulated by controllably variable intensity outputs of the optical device to artificially produce or enhance optical effects of the jewel.
In practice, the prior art articles of jewelry have incorporated a small cell/battery to energise the electronic circuitry and to power their light source. The power demands of the article of jewelry and the capacity of the cell determine the how long the life of the cell will be before it requires replacement. As a practical matter, it is a major requirement of the power supply that it can provide power for at least one full wearing, which can be for example from 5 to 10 hours.
Preferably, the article of jewelry embodying the present invention comprises a rechargeable power supply. Such a rechargeable power supply can meet the above life-span requirement without the need for and unduly large cell capacity, and also can advantageously avoid the problem of frequent battery replacement. The use of a rechargeable battery enables the article of jewelry to be recharged after each wearing when the article is not being worm, until its next wearing.
Preferably, the article of jewelry further comprises means for charging the power supply. The charging means may advantageously be arranged to receive power by indirect electrical connection to an external power supply. Accordingly, the need for electrical contacts, which can detract from the appearance of the article, between the article of jewelry and the external power source can be avoided. In a presently preferred embodiment of the invention, the indirect electrical connection is achieved by the charging means comprising a non-contact inductive loop circuit.
An external charging circuit, connected to the external power supply, can be built into and concealed within a jewelry stand, such as a ring tree, or a jewelry case/box. The user simply uses the stand or case in the normal way and the article is recharged without undue fuss when not in use. This provides an attractive way of recharging the power supply in the article of jewelry which requires no special instructions.
According to another aspect of the present invention there is provided a combination of an article of jewelry as described hereinabove, and a charging circuit external to said article, said external charging circuit being connectable to a permanent mains power supply.
According to another broad aspect of the present invention there is provided an article of jewelry comprising: means for illuminating a jewel of the article; and a rechargeable power supply for powering the illuminating means. As mentioned previously, this has the advantage of avoiding the costly and laborious task of regular battery replacement. In addition, the battery capacity can be selected to last just a single wearing of the article and so the size of the battery can advantageously be minimized.
The rechargeable power supply is preferably arranged to receive power by indirect electrical connection to an external power source. Therefore, the need for electrical contacts between the article of jewelry and the external power source can be avoided. This in turn prevents the appearance of the article from being unattractively altered to accommodate the contacts.
According to another broad aspect of the present invention there is provided a method of illuminating a jewel for simulating natural optical effects of the jewel, such as sparkle and scintillation, the method comprising: providing a light source adjacent the jewel for emitting light so as to illuminate the jewel; and controlling the light source to cause it to emit light pulses which are variable in their intensity, thereby simulating said natural optical effects of the jewel.
According to another broad aspect of the present invention there is provided a system for illuminating a jewel for simulating natural optical effects of the jewel, such as sparkle and scintillation, the system comprising: a light source positionable adjacent the jewel for emitting light so as to illuminate the jewel; and means for controlling the light source to cause it to emit light pulses which are variable in their intensity, thereby simulating said natural optical effects of the jewel.
The present invention also extends to an object incorporating a system as above described, wherein a portion of the object is illuminated by the system. For example, a portion of a mobile phone, or a clothing accessory such as a handbag, or even an portion of a dress could be illuminated by the system to enhance its attractiveness to the user.
In the presently preferred embodiments of the invention, the light source is a light emitting diode. However, this type of light source may be replaced by any suitable light source as long as it is readily controllable, is not unsuitably large for incorporation into an article of jewelry and does not consume unsuitably large amounts of energy. One alternative source of light is to use electronic luminous plastics materials, which emit a particular wavelength of light when an electrical current is passed through them. Different types of these plastics materials can be used to generate the required different colors of illumination for the jewel. Another alternative is to use a chemical light source which emits light by a chemically reactive process.
The present invention also extends to an article of clothing incorporating a one or more articles of jewelry as described above. For example, a clothes designer working at top couturier level can therefore design and make a dress or a jacket embroidered with scintillating jewels which would always exhibit their optimum optical characteristics due to the artificial illumination. The illumination of each jewel in the dress would be controlled from a central electronic system and the wiring between the jewels and the system would simply be incorporated into the lining of the dress. Also, there would be no need to provide real jewels as artificial jewels optimally illuminated would be quite effective in producing the desired effect at a fraction of the cost.